A wireless broadcast system, such as a Digital Video Broadcasting (DVB) system, may transmit data in a sequence of frames. For example, a DVB system may operate according to a DVB-Terrestrial 2nd Generation (T2) standard, a DVB-Next Generation Handheld (DVB-NGH) standard, Advanced Televisions Systems Committee (ATSC), Integrated Services Digital Broadcasting (ISDB), or Digital Multimedia Broadcasting (DMB).
Each broadcast frame typically includes a preamble section and a data section, which are time-multiplexed. For example, the data section carries data arranged in a number of data streams referred to as Physical Layer Pipes (PLPs). A PLP carries a service such as a video channel provided to a user.
Reception of the data from the frames, and reception of the data streams, may be assisted by signaling, which may be carried in the preamble of the frame, i.e., Out-of-Band (OB) signaling, and/or may be carried in the data section, e.g., of the preceding frame, i.e., In-Band (IB) signaling. The signaling may be referred to as physical layer signaling, or Layer 1 (L1) signaling.
The preamble section of a frame includes various parts, an L1-Config (configuration) part and an L1-Dyn (dynamic) part. The L1-config part typically carries information that is valid for each frame of a super-frame, and is typically the same for each frame of the super-frame. The L1-Dyn part carries information that may vary from one frame to the next.
With an increasing use of signal compression techniques and lower data rate services that may be more robust in particular in mobile environments, the number of PLPs carried by a sequence of frames is potentially large. For example, in DVB-T2, up to 255 PLPs may be supported.
Because at least some of the transmitted information varies between the different PLPs, the signaling information transmitted in the preamble portion may represent a large overhead per frame in terms of data capacity. In particular, the L1-Config part often takes up a high proportion (e.g., more than 60%) of the signaling information of the preamble section. Consequently, the overhead resulting from the L1-Config is particularly high.